Actual source code: ex1f.F90
1: program main
2: #include <petsc/finclude/petscvec.h>
3: use petscvec
4: implicit none
6: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
7: ! Variable declarations
8: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9: !
10: ! Variables:
11: ! x, y, w - vectors
12: ! z - array of vectors
14: Vec :: x,y,w
15: Vec, dimension(5) :: z
16: PetscReal :: norm,v,v1,v2
17: PetscInt, parameter :: &
18: ithree = 3, &
19: n = 20
20: PetscBool :: flg
21: PetscErrorCode :: ierr
22: PetscMPIInt :: rank
23: PetscScalar, parameter :: &
24: one = 1.0, &
25: two = 2.0, &
26: three = 3.0
27: PetscScalar :: dot
28: PetscScalar, dimension(3) :: dots
29: character(len=PETSC_MAX_PATH_LEN) :: name
30: PetscReal :: nfloat
32: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
33: ! Beginning of program
34: ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
36: PetscCallA(PetscInitialize(ierr))
37: PetscCallA(PetscOptionsGetInt(PETSC_NULL_OPTIONS,PETSC_NULL_CHARACTER,'-n',n,flg,ierr))
38: nfloat = n
39: PetscCallMPIA(MPI_Comm_rank(PETSC_COMM_WORLD,rank,ierr))
41: ! Create a vector, specifying only its global dimension.
42: ! When using VecCreate(), VecSetSizes() and VecSetFromOptions(),
43: ! the vector format (currently parallel
44: ! or sequential) is determined at runtime. Also, the parallel
45: ! partitioning of the vector is determined by PETSc at runtime.
46: !
47: PetscCallA(VecCreate(PETSC_COMM_WORLD,x,ierr))
48: PetscCallA(VecSetSizes(x,PETSC_DECIDE,n,ierr))
49: PetscCallA(VecSetFromOptions(x,ierr))
50: PetscCallA(VecGetType(x,name,ierr))
52: ! Duplicate some work vectors (of the same format and
53: ! partitioning as the initial vector).
55: PetscCallA(VecDuplicate(x,y,ierr))
56: PetscCallA(VecDuplicate(x,w,ierr))
58: ! Duplicate more work vectors (of the same format and
59: ! partitioning as the initial vector). Here we duplicate
60: ! an array of vectors, which is often more convenient than
61: ! duplicating individual ones.
63: PetscCallA(VecDuplicateVecs(x,ithree,z,ierr))
65: ! Set the vectors to entries to a constant value.
67: PetscCallA(VecSet(x,one,ierr))
69: PetscCallA(VecSet(y,two,ierr))
70: PetscCallA(VecSet(z(1),one,ierr))
71: PetscCallA(VecSet(z(2),two,ierr))
72: PetscCallA(VecSet(z(3),three,ierr))
74: ! Demonstrate various basic vector routines.
76: PetscCallA(VecDot(x,x,dot,ierr))
77: PetscCallA(VecMDot(x,ithree,z,dots,ierr))
79: ! Note: If using a complex numbers version of PETSc, then
80: ! PETSC_USE_COMPLEX is defined in the makefiles; otherwise,
81: ! (when using real numbers) it is undefined.
83: if (rank .eq. 0) then
84: #if defined(PETSC_USE_COMPLEX)
85: write(6,100) int(PetscRealPart(dot))
86: write(6,110) int(PetscRealPart(dots(1))),int(PetscRealPart(dots(2))),int(PetscRealPart(dots(3)))
87: #else
88: write(6,100) int(dot)
89: write(6,110) int(dots(1)),int(dots(2)),int(dots(3))
90: #endif
91: write(6,120)
92: endif
93: 100 format ('Vector length ',i6)
94: 110 format ('Vector length ',3(i6))
95: 120 format ('All other values should be near zero')
97: PetscCallA(VecScale(x,two,ierr))
98: PetscCallA(VecNorm(x,NORM_2,norm,ierr))
99: v = abs(norm-2.0*sqrt(nfloat))
100: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
101: if (rank == 0) write(6,130) v
102: 130 format ('VecScale ',1pe9.2)
104: PetscCallA(VecCopy(x,w,ierr))
105: PetscCallA(VecNorm(w,NORM_2,norm,ierr))
106: v = abs(norm-2.0*sqrt(nfloat))
107: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
108: if (rank == 0) write(6,140) v
109: 140 format ('VecCopy ',1pe9.2)
111: PetscCallA(VecAXPY(y,three,x,ierr))
112: PetscCallA(VecNorm(y,NORM_2,norm,ierr))
113: v = abs(norm-8.0*sqrt(nfloat))
114: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
115: if (rank == 0) write(6,150) v
116: 150 format ('VecAXPY ',1pe9.2)
118: PetscCallA(VecAYPX(y,two,x,ierr))
119: PetscCallA(VecNorm(y,NORM_2,norm,ierr))
120: v = abs(norm-18.0*sqrt(nfloat))
121: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
122: if (rank == 0) write(6,160) v
123: 160 format ('VecAYXP ',1pe9.2)
125: PetscCallA(VecSwap(x,y,ierr))
126: PetscCallA(VecNorm(y,NORM_2,norm,ierr))
127: v = abs(norm-2.0*sqrt(nfloat))
128: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
129: if (rank == 0) write(6,170) v
130: 170 format ('VecSwap ',1pe9.2)
132: PetscCallA(VecNorm(x,NORM_2,norm,ierr))
133: v = abs(norm-18.0*sqrt(nfloat))
134: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
135: if (rank == 0) write(6,180) v
136: 180 format ('VecSwap ',1pe9.2)
138: PetscCallA(VecWAXPY(w,two,x,y,ierr))
139: PetscCallA(VecNorm(w,NORM_2,norm,ierr))
140: v = abs(norm-38.0*sqrt(nfloat))
141: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
142: if (rank == 0) write(6,190) v
143: 190 format ('VecWAXPY ',1pe9.2)
145: PetscCallA(VecPointwiseMult(w,y,x,ierr))
146: PetscCallA(VecNorm(w,NORM_2,norm,ierr))
147: v = abs(norm-36.0*sqrt(nfloat))
148: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
149: if (rank == 0) write(6,200) v
150: 200 format ('VecPointwiseMult ',1pe9.2)
152: PetscCallA(VecPointwiseDivide(w,x,y,ierr))
153: PetscCallA(VecNorm(w,NORM_2,norm,ierr))
154: v = abs(norm-9.0*sqrt(nfloat))
155: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
156: if (rank == 0) write(6,210) v
157: 210 format ('VecPointwiseDivide ',1pe9.2)
159: dots(1) = one
160: dots(2) = three
161: dots(3) = two
162: PetscCallA(VecSet(x,one,ierr))
163: PetscCallA(VecMAXPY(x,ithree,dots,z,ierr))
164: PetscCallA(VecNorm(z(1),NORM_2,norm,ierr))
165: v = abs(norm-sqrt(nfloat))
166: if (v .gt. -PETSC_SMALL .and. v .lt. PETSC_SMALL) v = 0.0
167: PetscCallA(VecNorm(z(2),NORM_2,norm,ierr))
168: v1 = abs(norm-2.0*sqrt(nfloat))
169: if (v1 .gt. -PETSC_SMALL .and. v1 .lt. PETSC_SMALL) v1 = 0.0
170: PetscCallA(VecNorm(z(3),NORM_2,norm,ierr))
171: v2 = abs(norm-3.0*sqrt(nfloat))
172: if (v2 .gt. -PETSC_SMALL .and. v2 .lt. PETSC_SMALL) v2 = 0.0
173: if (rank .eq. 0) write(6,220) v,v1,v2
174: 220 format ('VecMAXPY ',3(2x,1pe9.2))
176: ! Free work space. All PETSc objects should be destroyed when they
177: ! are no longer needed.
179: PetscCallA(VecDestroy(x,ierr))
180: PetscCallA(VecDestroy(y,ierr))
181: PetscCallA(VecDestroy(w,ierr))
182: PetscCallA(VecDestroyVecs(ithree,z,ierr))
183: PetscCallA(PetscFinalize(ierr))
185: end
187: !
188: !/*TEST
189: !
190: ! test:
191: ! suffix: 1
192: !
193: ! test:
194: ! suffix: 2
195: ! nsize: 2
196: !
197: !TEST*/